Wake County

NCDOT’s 540 project must tread carefully around a protected stream mussel

Tim Savidge uses a viewer to look for the endangered dwarf wedge mussel in Swift Creek in Johnston County near Clayton in 2010.
Tim Savidge uses a viewer to look for the endangered dwarf wedge mussel in Swift Creek in Johnston County near Clayton in 2010. cliddy@newsobserver.com

North Carolina highway planners still have work to do before the U.S. Fish and Wildlife Service can sign off on a proposed six-lane toll road that would pollute the habitat of an endangered stream creature, the dwarf wedgemussel.

State and federal environmental regulators OK’d a decision by the state Department of Transportation in April to move forward with its preferred path for extending the 540 Outer Loop across southern Wake County: the so-called Orange Route from Holly Springs to Interstate 40 south of Garner. Their preliminary approval allowed DOT to put aside other routes it had been required to consider.

Now, officials with the regulatory agencies say they will push DOT for what could be expensive measures to minimize the environmental harm that would come directly from the proposed road – and, indirectly, from new homes and other construction that would be stimulated by this major highway, which will create an I-40 bypass around Raleigh.

The U.S. Army Corps of Engineers will press for construction methods and structural design details that can reduce the miles of streams and acres of wetlands affected by what DOT calls the Complete 540 project.

“And if we think they need to minimize that some more, we will recommend that” before issuing the necessary permits, Eric Alsmeyer, a Raleigh-based regulatory project manager for the Corps of Engineers, said last week.

We have major concerns about this project because of its potential effects on the dwarf wedgemussel.

Gary Jordan, U.S. Fish and Wildlife biologist

While other state and federal agencies also have a say, the Fish and Wildlife Service holds the most power to make DOT alter its plans or take expensive measures on behalf of a small creature that is protected by one of the nation’s strongest environmental laws, the Endangered Species Act.

“We have major concerns about this project because of its potential effects on the dwarf wedgemussel,” said Gary Jordan, a Raleigh-based wildlife biologist for Fish and Wildlife. “We have not yet done our full analysis. We have to do a jeopardy analysis, to determine whether the project would jeopardize the continued existence of the species.”

DOT has acknowledged, in a 122-page report explaining its Orange Route choice, that environmental studies show that “the long-term viability of the (dwarf wedgemussel) population in Swift Creek appears to be threatened.”

It’s a freshwater mussel, brown-shelled and thumb-sized, that dwells in streambeds and banks. The dwarf wedgemussel has affected road and public works projects in several parts of the state since it was added to the federal endangered species list in 1990. Because of its presence in the Swift Creek watershed just south of the planned 540 link, DOT incurred years of delays and millions of dollars in added costs when it built the U.S. 70 Clayton Bypass, which opened in 2008.

Mussel jeopardy

The dwarf wedgemussel is found in greater numbers in northeastern states, and Wake County is near the southern end of its range, Jordan said. But state and federal wildlife agencies have declared Swift Creek “essential” to the endangered mussel’s survival and recovery, so the 540 plan is expected to receive close scrutiny from Fish and Wildlife.

Yeah, it’s going to be up there on the high end, for sure, when you compare it to other projects around the state.

Brian Yamamoto, NCDOT engineer

To mitigate any pollution-related threats to the mussel’s health, DOT says it will consider long-range monitoring of stream water and mussel habitat quality – and possibly an elaborate program to propagate mussels in captivity and release them in the creek. These and other mitigation measures could be expensive.

“Yeah, it’s going to be up there on the high end, for sure, when you compare it to other projects around the state,” said Brian Yamamoto, a DOT engineer overseeing the project.

Jordan says he cannot recall a case in North Carolina where Fish and Wildlife ruled that a highway project would jeopardize the future of an endangered species. The jeopardy analysis will not begin until DOT is ready to request it.

If the outcome is favorable to the Orange Route project, Fish and Wildlife will give DOT legal authority for the “incidental take” of dwarf wedgemussels – which can include anything from killing them outright to muddying their habitat. If it is unfavorable, DOT will be required to come up with a “prudent alternative” to the Orange Route road.

Environmental critics already have asserted that the project would indeed jeopardize the existence of the species and that the road cannot legally be built. In a 58-page letter to DOT in January, the Southern Environmental Law Center focused on planned interchanges south of Garner that would connect 540 with I-40 and the Clayton Bypass, which would be built on top of Swift Creek and several tributaries.

“These routes would tear up these critical portions of Swift Creek, and the dwarf wedgemussel would suffer further direct impacts from erosion and siltation resulting from construction of the road,” SELC attorney Kym Hunter wrote.

The environmental law group does not favor any of the alternatives DOT considered for the Complete 540 project – including the universally unpopular Red Route, which would avoid mussel damage while destroying businesses and neighborhoods in Garner. Instead, the SELC says the project will cost too much and questions the justification for completing 540.

Bruce Siceloff: 919-829-4527, @Road_Worrier

How much and how soon?

DOT plans to finish the 540 Outer Loop in three phases, 28.4 miles long in all. Here are current cost estimates and construction schedules, all subject to revision in future years:

Phase 1: N.C. 55 at Holly Springs to U.S. 401 near Wake Tech: $405.4 million. Design-build contract to be awarded in fiscal year 2017-2018 to a partnership of private companies that would complete the design and engineering work, and then build it. Actual construction could begin as soon as 2018.

Phase 2: U.S. 401 to I-40 near Garner: $565.1 million. Design-build contract in 2023-2024.

Phase 3: I-40 to I-495 (U.S. 64/264) near Knightdale: $520.7 million. Not yet scheduled, probably some years after 2025.